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LOW severity

GHSA-4vrg-r928-h5vv spicedb

LOW

GHSA-4vrg-r928-h5vv is a low-severity (CVSS 3.7) CWE-863 vulnerability in github.com/authzed/spicedb. A fix is available for github.com/authzed/spicedb — see the affected versions and patch details below.

SpiceDB: Checks involving relations with caveats can result in unconditional permission when conditional permission is expected

Also known asCVE-2026-55866GO-2026-5133
Published
Jun 19, 2026
Updated
Jun 25, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-4vrg-r928-h5vv.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs13th percentile — riskier than 13% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

GHSA-4vrg-r928-h5vv plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 374,847 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

1 pkg affected
🐹github.com/authzed/spicedb

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Under concurrency, CheckPermission and CheckBulkPermissions can return PERMISSIONSHIP_HAS_PERMISSION for a (resource, permission, subject) whose correct answer is PERMISSIONSHIP_CONDITIONAL_PERMISSION.

You are impacted if all of the following hold:

  1. Your schema has a permission combining relations with an intersection or exclusion, where a subject reaches it through a caveated branch and a non-caveated branch. For example:
  definition user {}

  caveat some_caveat(somecondition int) { somecondition == 42 }

  definition document {
    relation reader: user | user with some_caveat
    relation writer: user
    relation banned: user
    permission has_permission = (reader & writer) - banned
  }
  1. A subject reaches the permission via the caveated edge:
  document:firstdoc#reader@user:caveatedreader[some_caveat]
  document:firstdoc#writer@user:caveatedreader
  1. Your workload issues LookupResources with a context request parameter, concurrently with CheckPermission/CheckBulkPermissions for the same subject/resource, and
  2. The dispatch result cache is enabled.

When all of the above are true, there is an intermittent window in which:

CheckPermission(document:firstdoc, has_permission, user:caveatedreader) → HAS_PERMISSION (incorrect; should be CONDITIONAL_PERMISSION)

CheckPermission(document:firstdoc, has_permission, user:caveatedreader, context = {"somecondition": 41}) → HAS_PERMISSION (incorrect; should be NO_PERMISSION)

Patches

v1.54.0

Workarounds

Disable the dispatch result cache (ClusterDispatchCacheConfig and DispatchCacheConfig)

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/authzed/spicedb1.34.0&&< 1.54.01.54.0go get github.com/authzed/spicedb@v1.54.0

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/authzed/spicedb, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update github.com/authzed/spicedb to 1.54.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4vrg-r928-h5vv is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-4vrg-r928-h5vv can be triaged on real exposure rather than presence alone.

Tailored to GHSA-4vrg-r928-h5vv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact Under concurrency, `CheckPermission` and `CheckBulkPermissions` can return `PERMISSIONSHIP_HAS_PERMISSION` for a (resource, permission, subject) whose correct answer is `PERMISSIONSHIP_CONDITIONAL_PERMISSION`. You are impacted if **all** of the following hold: 1. Your schema has a permission combining relations with an intersection or exclusion, where a subject reaches it through a caveated branch and a non-caveated branch. For example: ```zed definition user {} caveat some_caveat(somecondition int) { somecondition == 42 } definition document { relation reader:
O3 Security · Impact-Aware SCA

Is GHSA-4vrg-r928-h5vv in your dependencies?

O3 Security finds GHSA-4vrg-r928-h5vv across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-4vrg-r928-h5vv: spicedb (Low 3.7) | O3 Security